Similar material simulation experiment on destressing effects of the deep thick coal seam with high burst liability after mining upper and lower protective seams

In order to study the destressing effects of the deep thick coal seams with high burst liability after mining upper and lower protective seams,the method of similar material simulation experiment is adopted to analyze the rule of the stress change,to compute the lower reasonable distressing angle of the lower protective seam,and to find the lower tunnel’s reasonable position of the protected seam by monitoring the stress change of the protected seam in the process of mining the protective seam and the stable state.The reasonable position of the upper protective seam workface is chosen by comparing the distressing effects of the twice simulation experiments of mining the upper protective seam.The upper tunnel region of the protected seam is still a high concentrative area with easy occurrence of rock burst despite mining the lower protective seam.After mining the upper protective seam,the stress in this area falls obviously,so it proves that the upper protective seam distresses obviously.The experiment verifies that the "rebound" phenomenon occurs on the earth surface before rock burst with high energy in mining.This study provides the theoretical guidance for the mining design of the workface and it is very important to prevent rock burst in practice.